in Dr. Seuss children’s books Horton Hears a Who!Elephant Horton desperately tries to save Howell’s world. Small to the point of dust, it turns out Horton should be worried about himself too: according to new research into the species that inhabit the island, The smallest and largest species are most threatened with extinction.
An international team of evolutionary biologists has led a study of the Hortons and Whos of the world’s islands, finding that the more they differ in body mass from those on the mainland, the more likely they are. The more they are at risk of extinction. This conclusion is made worse by the team’s further finding that human arrival on remote islands about 12,000 years ago increased the rate of extinction by more than tenfold. Their study was published March 9 in science.
“We found that species with extreme changes in body size That is the extreme dwarfs and giants. It is likely to be threatened or extinct,” said Roberto Rossi, a paleontologist at the Museum of Natural History in Berlin and The co-authors of the study told The Daily Beast in an email: “Eventually, many of our dwarfs and giants have become so ecologically naive that they perish under what Darwin describes as the “failure of humanity.” ‘Stranger’s Skill’, a destructive effect often inflicted by foreign races. including humans.”
naturally These islands have led to the evolution of unique life forms. which cannot be found anywhere else The autonomous island ecosystem has peculiar resources and pressures that support extremely peculiar species. especially large and small creatures sample textbook of This “island syndrome” is a different species of turtle. Living on the Galapagos Islands: The giant tortoise is found on all seven islands and nowhere else. And each island is home to a different subspecies of turtles. On the other end of the spectrum, sticking syndromes The island of Crete gave birth to the tiny, extinct mammoths. The adult body is the size of a baby elephant.
As a paleontologist working on the island’s mammals, Rozzi said he has always been fascinated by these unique evolutionary changes. “Holding fossilized pygmy elephant and hippo bones that have shrunk to less than a tenth of the mass of their mainland ancestors is very special. Unfortunately, these evolutionary wonders are often threatened or extinct,” he said. “The correlation between their characteristics and vulnerability” and documented extinction over a long period of time.
The researchers analyzed nearly 8,000 animal fossils from 182 islands and used data from the IUCN Red List to determine the proportion of island and mainland species that are threatened or extinct. To determine whether an island species How big or small is it? The team compared its mass with that of its nearest mainland relatives.
“Ultimately, many of our dwarfs and giants become ecologically naive and perish under what Darwin describes as the ‘The handiwork of strangers’, which is often the devastating effect of alien races. including humans”
— Roberto Rozzi, Museum of Natural History, Berlin
Overall, they found that large differences in body mass between island and mainland animals were associated with a higher likelihood of a species being threatened or extinct. This metric is a better predictor of extinction risk than body mass alone, or as Rozzi puts it, “it’s not that big. per second That’s how big the difference is between the mainland and the island.”
Why is relative size more important for the existence of a species than size alone? Perhaps comparing the difference between the body mass of the island and the mainland is a more accurate indicator of how strange the animal is. (or in biological terms How ecologically innocent it is. Changes to the island environment or an invasion from mainland species could put these monsters in danger.
Alternatively, large differences in size between island species and their mainland relatives may mean that drastic changes must occur along the way of evolution. Much smaller species of mammoths may have fused bones. Or, much larger turtles may take longer to develop in fragile conditions.
Researchers have found that the continued existence of humans on the islands of the world began tens of thousands of years ago. Still, human interference does not change the overall trend that relatively large and smaller species are most endangered. This may be because predators prioritize much larger species for bigger rewards. or smaller breeds because of shyness or for novelty For species that are larger or smaller than what mainland humans are used to.
The current outlook for the global extinction crisis is not very optimistic. But Rossi and his team hope the findings will help highlight conservation efforts for the island’s much larger and smaller species. They write in their research that these creatures are “The last surviving evolutionary wonder of island life,” Whoville is worth protecting.
